//------------------------------------------------------------------------------
// <copyright file="SqlMoney.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
//  </copyright>
// <owner current="true" primary="true">junfang</owner>
// <owner current="true" primary="false">Microsoft</owner>
// <owner current="true" primary="false">Microsoft</owner>
//------------------------------------------------------------------------------

//**************************************************************************
// @File: SqlMoney.cs
//
// Create by:    JunFang
//
// Purpose: Implementation of SqlMoney which is equivalent to
//            data type "money" in SQL Server
//
// Notes:
//
// History:
//
//   09/17/99  JunFang    Created and implemented as first drop.
//
// @EndHeader@
//**************************************************************************

using System;
using System.Data.Common;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Globalization;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;

namespace System.Data.SqlTypes {

    /// <devdoc>
    ///    <para>
    ///       Represents a currency value ranging from
    ///       -2<superscript term='63'/> (or -922,337,203,685,477.5808) to 2<superscript term='63'/> -1 (or
    ///       +922,337,203,685,477.5807) with an accuracy to
    ///       a ten-thousandth of currency unit to be stored in or retrieved from a
    ///       database.
    ///    </para>
    /// </devdoc>
    [Serializable]
    [StructLayout(LayoutKind.Sequential)]
    [XmlSchemaProvider("GetXsdType")]
    public struct SqlMoney : INullable, IComparable, IXmlSerializable {
        private bool m_fNotNull; // false if null
        private long m_value;

        // SQL Server stores money8 as ticks of 1/10000.
        internal const int x_iMoneyScale = 4;
        private const long x_lTickBase = 10000;
        private const double x_dTickBase = (double)x_lTickBase;

        private const long MinLong = unchecked((long)0x8000000000000000L) / x_lTickBase;
        private const long MaxLong = 0x7FFFFFFFFFFFFFFFL / x_lTickBase;

        // constructor
        // construct a Null
        private SqlMoney(bool fNull) {
            m_fNotNull = false;
            m_value = 0;
        }

        // Constructs from a long value without scaling. The ignored parameter exists
        // only to distinguish this constructor from the constructor that takes a long.
        // Used only internally.
        internal SqlMoney(long value, int ignored) {
            m_value = value;
            m_fNotNull = true;
        }

        /// <devdoc>
        ///    <para>
        ///       Initializes a new instance of the <see cref='System.Data.SqlTypes.SqlMoney'/> class with the value given.
        ///    </para>
        /// </devdoc>
        public SqlMoney(int value) {
            m_value = (long)value * x_lTickBase;
            m_fNotNull = true;
        }

        /// <devdoc>
        ///    <para>
        ///       Initializes a new instance of the <see cref='System.Data.SqlTypes.SqlMoney'/> class with the value given.
        ///    </para>
        /// </devdoc>
        public SqlMoney(long value) {
            if (value < MinLong || value > MaxLong)
                throw new OverflowException(SQLResource.ArithOverflowMessage);
            m_value = value * x_lTickBase;
            m_fNotNull = true;
        }

        /// <devdoc>
        ///    <para>
        ///       Initializes a new instance of the <see cref='System.Data.SqlTypes.SqlMoney'/> class with the value given.
        ///    </para>
        /// </devdoc>
        public SqlMoney(Decimal value) {
            // Since Decimal is a value type, operate directly on value, don't worry about changing it.
            SqlDecimal snum = new SqlDecimal(value);
            snum.AdjustScale(x_iMoneyScale - snum.Scale, true);
            Debug.Assert(snum.Scale == x_iMoneyScale);

            if (snum.m_data3 != 0 || snum.m_data4 != 0)
                throw new OverflowException(SQLResource.ArithOverflowMessage);

            bool fPositive = snum.IsPositive;
            ulong ulValue = (ulong)snum.m_data1 + ( ((ulong)snum.m_data2) << 32 );
            if (fPositive && ulValue > (ulong)(Int64.MaxValue) ||
                !fPositive && ulValue > unchecked((ulong)(Int64.MinValue)))
                throw new OverflowException(SQLResource.ArithOverflowMessage);

            m_value = fPositive ? (long)ulValue : unchecked(- (long)ulValue);
            m_fNotNull = true;
        }

        /// <devdoc>
        ///    <para>
        ///       Initializes a new instance of the <see cref='System.Data.SqlTypes.SqlMoney'/> class with the value given.
        ///    </para>
        /// </devdoc>
        public SqlMoney(double value) : this(new Decimal(value)) {
        }


        // INullable
        /// <devdoc>
        ///    <para>
        ///       Gets a value indicating whether the <see cref='System.Data.SqlTypes.SqlMoney.Value'/>
        ///       property is assigned to null.
        ///    </para>
        /// </devdoc>
        public bool IsNull {
            get { return !m_fNotNull;}
        }

        // property: Value
        /// <devdoc>
        ///    <para>
        ///       Gets or sets the monetary value of an instance of the <see cref='System.Data.SqlTypes.SqlMoney'/>
        ///       class.
        ///    </para>
        /// </devdoc>
        public Decimal Value {
            get {
                if (m_fNotNull)
                    return ToDecimal();
                else
                    throw new SqlNullValueException();
            }
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public Decimal ToDecimal() {
            if(IsNull)
                throw new SqlNullValueException();

            bool fNegative = false;
            long value = m_value;
            if (m_value < 0) {
                fNegative = true;
                value = - m_value;
            }

            return new Decimal(unchecked((int)value), unchecked((int)(value >> 32)), 0, fNegative, (byte)x_iMoneyScale);
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public long ToInt64() {
            if(IsNull)
                throw new SqlNullValueException();

            long ret = m_value / (x_lTickBase / 10);
            bool fPositive = (ret >= 0);
            long remainder = ret % 10;
            ret = ret / 10;

            if (remainder >= 5) {
                if (fPositive)
                    ret ++;
                else
                    ret --;
            }

            return ret;
        }

        internal long ToSqlInternalRepresentation() {
            if(IsNull)
                throw new SqlNullValueException();

            return m_value;
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public int ToInt32() {
            return checked((int)(ToInt64()));
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public double ToDouble() {
            return Decimal.ToDouble(ToDecimal());
        }

        // Implicit conversion from Decimal to SqlMoney
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static implicit operator SqlMoney(Decimal x) {
            return new SqlMoney(x);
        }

        // Explicit conversion from Double to SqlMoney
        public static explicit operator SqlMoney(double x) {
            return new SqlMoney(x);
        }

        // Implicit conversion from long to SqlMoney
        public static implicit operator SqlMoney(long x) {
            return new SqlMoney(new Decimal(x));
        }

        // Explicit conversion from SqlMoney to Decimal. Throw exception if x is Null.
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static explicit operator Decimal(SqlMoney x) {
            return x.Value;
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public override String ToString() {
            if (this.IsNull) {
                return SQLResource.NullString;
            }
            Decimal money = ToDecimal();
            // Formatting of SqlMoney: At least two digits after decimal point
            return money.ToString("#0.00##", (IFormatProvider)null);
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static SqlMoney Parse(String s) {
            // Try parsing the format of '#0.00##' generated by ToString() by using the
            // culture invariant NumberFormatInfo as well as the current culture's format
            //
            Decimal d;
            SqlMoney money;

            const NumberStyles SqlNumberStyle = 
                     NumberStyles.AllowCurrencySymbol |
                     NumberStyles.AllowDecimalPoint |
                     NumberStyles.AllowParentheses | 
                     NumberStyles.AllowTrailingSign |
                     NumberStyles.AllowLeadingSign |
                     NumberStyles.AllowTrailingWhite |
                     NumberStyles.AllowLeadingWhite;

            if ( s == SQLResource.NullString) {
                money = SqlMoney.Null;
            }
            else if (Decimal.TryParse(s, SqlNumberStyle, NumberFormatInfo.InvariantInfo, out d)) {
                money = new SqlMoney(d);
            }
            else {
                money = new SqlMoney(Decimal.Parse(s, NumberStyles.Currency, NumberFormatInfo.CurrentInfo));
            }
            
            return money;
        }

        // Unary operators
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static SqlMoney operator -(SqlMoney x) {
            if (x.IsNull)
                return Null;
            if (x.m_value == MinLong)
                throw new OverflowException(SQLResource.ArithOverflowMessage);
            return new SqlMoney(-x.m_value, 0);
        }


        // Binary operators

        // Arithmetic operators
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static SqlMoney operator +(SqlMoney x, SqlMoney y) {
            try {
                return(x.IsNull || y.IsNull) ? Null : new SqlMoney(checked(x.m_value + y.m_value), 0);
            }
            catch (OverflowException) {
                throw new OverflowException(SQLResource.ArithOverflowMessage);
            }
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static SqlMoney operator -(SqlMoney x, SqlMoney y) {
            try {
                return(x.IsNull || y.IsNull) ? Null : new SqlMoney(checked(x.m_value - y.m_value), 0);
            }
            catch (OverflowException) {
                throw new OverflowException(SQLResource.ArithOverflowMessage);
            }
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static SqlMoney operator *(SqlMoney x, SqlMoney y) {
            return (x.IsNull || y.IsNull) ? Null :
		new SqlMoney(Decimal.Multiply(x.ToDecimal(), y.ToDecimal()));
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static SqlMoney operator /(SqlMoney x, SqlMoney y) {
            return (x.IsNull || y.IsNull) ? Null :
		new SqlMoney(Decimal.Divide(x.ToDecimal(), y.ToDecimal()));
        }


        // Implicit conversions

        // Implicit conversion from SqlBoolean to SqlMoney
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static explicit operator SqlMoney(SqlBoolean x) {
            return x.IsNull ? Null : new SqlMoney((int)x.ByteValue);
        }

        // Implicit conversion from SqlByte to SqlMoney
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static implicit operator SqlMoney(SqlByte x) {
            return x.IsNull ? Null : new SqlMoney((int)x.Value);
        }

        // Implicit conversion from SqlInt16 to SqlMoney
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static implicit operator SqlMoney(SqlInt16 x) {
            return x.IsNull ? Null : new SqlMoney((int)x.Value);
        }

        // Implicit conversion from SqlInt32 to SqlMoney
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static implicit operator SqlMoney(SqlInt32 x) {
            return x.IsNull ? Null : new SqlMoney(x.Value);
        }

        // Implicit conversion from SqlInt64 to SqlMoney
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static implicit operator SqlMoney(SqlInt64 x) {
            return x.IsNull ? Null : new SqlMoney(x.Value);
        }


        // Explicit conversions

        // Explicit conversion from SqlSingle to SqlMoney
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static explicit operator SqlMoney(SqlSingle x) {
            return x.IsNull ? Null : new SqlMoney((double)x.Value);
        }

        // Explicit conversion from SqlDouble to SqlMoney
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static explicit operator SqlMoney(SqlDouble x) {
            return x.IsNull ? Null : new SqlMoney(x.Value);
        }

        // Explicit conversion from SqlDecimal to SqlMoney
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static explicit operator SqlMoney(SqlDecimal x) {
            return x.IsNull ? SqlMoney.Null : new SqlMoney(x.Value);
        }

        // Explicit conversion from SqlString to SqlMoney
        // Throws FormatException or OverflowException if necessary.
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static explicit operator SqlMoney(SqlString x) {
            return x.IsNull ? Null : new SqlMoney(Decimal.Parse(x.Value,NumberStyles.Currency,null));
        }


        // Builtin functions

        // Overloading comparison operators
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static SqlBoolean operator==(SqlMoney x, SqlMoney y) {
            return(x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value == y.m_value);
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static SqlBoolean operator!=(SqlMoney x, SqlMoney y) {
            return ! (x == y);
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static SqlBoolean operator<(SqlMoney x, SqlMoney y) {
            return(x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value < y.m_value);
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static SqlBoolean operator>(SqlMoney x, SqlMoney y) {
            return(x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value > y.m_value);
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static SqlBoolean operator<=(SqlMoney x, SqlMoney y) {
            return(x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value <= y.m_value);
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static SqlBoolean operator>=(SqlMoney x, SqlMoney y) {
            return(x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value >= y.m_value);
        }


        //--------------------------------------------------
        // Alternative methods for overloaded operators
        //--------------------------------------------------

        // Alternative method for operator +
        public static SqlMoney Add(SqlMoney x, SqlMoney y) {
            return x + y;
        }
        // Alternative method for operator -
        public static SqlMoney Subtract(SqlMoney x, SqlMoney y) {
            return x - y;
        }

        // Alternative method for operator *
        public static SqlMoney Multiply(SqlMoney x, SqlMoney y) {
            return x * y;
        }

        // Alternative method for operator /
        public static SqlMoney Divide(SqlMoney x, SqlMoney y) {
            return x / y;
        }

        // Alternative method for operator ==
        public static SqlBoolean Equals(SqlMoney x, SqlMoney y) {
            return (x == y);
        }

        // Alternative method for operator !=
        public static SqlBoolean NotEquals(SqlMoney x, SqlMoney y) {
            return (x != y);
        }

        // Alternative method for operator <
        public static SqlBoolean LessThan(SqlMoney x, SqlMoney y) {
            return (x < y);
        }

        // Alternative method for operator >
        public static SqlBoolean GreaterThan(SqlMoney x, SqlMoney y) {
            return (x > y);
        }

        // Alternative method for operator <=
        public static SqlBoolean LessThanOrEqual(SqlMoney x, SqlMoney y) {
            return (x <= y);
        }

        // Alternative method for operator >=
        public static SqlBoolean GreaterThanOrEqual(SqlMoney x, SqlMoney y) {
            return (x >= y);
        }

        // Alternative method for conversions.

        public SqlBoolean ToSqlBoolean() {
            return (SqlBoolean)this;
        }

        public SqlByte ToSqlByte() {
            return (SqlByte)this;
        }

        public SqlDouble ToSqlDouble() {
            return (SqlDouble)this;
        }

        public SqlInt16 ToSqlInt16() {
            return (SqlInt16)this;
        }

        public SqlInt32 ToSqlInt32() {
            return (SqlInt32)this;
        }

        public SqlInt64 ToSqlInt64() {
            return (SqlInt64)this;
        }

        public SqlDecimal ToSqlDecimal() {
            return (SqlDecimal)this;
        }

        public SqlSingle ToSqlSingle() {
            return (SqlSingle)this;
        }

        public SqlString ToSqlString() {
            return (SqlString)this;
        }


        // IComparable
        // Compares this object to another object, returning an integer that
        // indicates the relationship.
        // Returns a value less than zero if this < object, zero if this = object,
        // or a value greater than zero if this > object.
        // null is considered to be less than any instance.
        // If object is not of same type, this method throws an ArgumentException.
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public int CompareTo(Object value) {
            if (value is SqlMoney) {
                SqlMoney i = (SqlMoney)value;

                return CompareTo(i);
            }
            throw ADP.WrongType(value.GetType(), typeof(SqlMoney));
        }

        public int CompareTo(SqlMoney value) {
            // If both Null, consider them equal.
            // Otherwise, Null is less than anything.
            if (IsNull)
                return value.IsNull ? 0  : -1;
            else if (value.IsNull)
                return 1;

            if (this < value) return -1;
            if (this > value) return 1;
            return 0;
        }

        // Compares this instance with a specified object
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public override bool Equals(Object value) {
            if (!(value is SqlMoney)) {
                return false;
            }

            SqlMoney i = (SqlMoney)value;

            if (i.IsNull || IsNull)
                return (i.IsNull && IsNull);
            else
                return (this == i).Value;
        }

        // For hashing purpose
        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public override int GetHashCode() {
            // Don't use Value property, because Value will convert to Decimal, which is not necessary.
            return IsNull ? 0 : m_value.GetHashCode();
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        XmlSchema IXmlSerializable.GetSchema() { return null; }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        void IXmlSerializable.ReadXml(XmlReader reader) {
            string isNull = reader.GetAttribute("nil", XmlSchema.InstanceNamespace);
            if (isNull != null && XmlConvert.ToBoolean(isNull)) {
                // VSTFDevDiv# 479603 - SqlTypes read null value infinitely and never read the next value. Fix - Read the next value.
                reader.ReadElementString();
                this.m_fNotNull = false;
            }
            else {
                SqlMoney money = new SqlMoney(XmlConvert.ToDecimal(reader.ReadElementString()));
                this.m_fNotNull = money.m_fNotNull;
                this.m_value = money.m_value;
            }
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        void IXmlSerializable.WriteXml(XmlWriter writer) {
            if (IsNull) {
                writer.WriteAttributeString("xsi", "nil", XmlSchema.InstanceNamespace, "true");
            }
            else {
                writer.WriteString( XmlConvert.ToString(ToDecimal()) );
            }
        }

        /// <devdoc>
        ///    <para>[To be supplied.]</para>
        /// </devdoc>
        public static XmlQualifiedName GetXsdType(XmlSchemaSet schemaSet) {
            return new XmlQualifiedName("decimal", XmlSchema.Namespace);
        }

        /// <devdoc>
        ///    <para>
        ///       Represents a null value that can be assigned to
        ///       the <see cref='System.Data.SqlTypes.SqlMoney.Value'/> property of an instance of
        ///       the <see cref='System.Data.SqlTypes.SqlMoney'/>class.
        ///    </para>
        /// </devdoc>
        public static readonly SqlMoney Null        = new SqlMoney(true);

        /// <devdoc>
        ///    <para>
        ///       Represents the zero value that can be assigned to the <see cref='System.Data.SqlTypes.SqlMoney.Value'/> property of an instance of
        ///       the <see cref='System.Data.SqlTypes.SqlMoney'/> class.
        ///    </para>
        /// </devdoc>
        public static readonly SqlMoney Zero        = new SqlMoney(0);

        /// <devdoc>
        ///    <para>
        ///       Represents the minimum value that can be assigned
        ///       to <see cref='System.Data.SqlTypes.SqlMoney.Value'/> property of an instance of
        ///       the <see cref='System.Data.SqlTypes.SqlMoney'/>
        ///       class.
        ///    </para>
        /// </devdoc>
        public static readonly SqlMoney MinValue    = new SqlMoney(unchecked((long)0x8000000000000000L), 0);

        /// <devdoc>
        ///    <para>
        ///       Represents the maximum value that can be assigned to
        ///       the <see cref='System.Data.SqlTypes.SqlMoney.Value'/> property of an instance of
        ///       the <see cref='System.Data.SqlTypes.SqlMoney'/>
        ///       class.
        ///    </para>
        /// </devdoc>
        public static readonly SqlMoney MaxValue    = new SqlMoney(0x7FFFFFFFFFFFFFFFL, 0);

    } // SqlMoney

} // namespace System.Data.SqlTypes
